Update pip to 19.1.1

[pyup-bot]

This PR updates pip from 19.0.3 to 19.1.1.

Changelog

19.1.1

===================

Features
--------

- Restore ``pyproject.toml`` handling to how it was with pip 19.0.3 to prevent
the need to add ``--no-use-pep517`` when installing in editable mode. (`6434 <https://github.com/pypa/pip/issues/6434>`_)

Bug Fixes
---------

- Fix a regression that caused `` to be quoted in pypiserver links.
This interfered with parsing the revision string from VCS urls. (`6440 <https://github.com/pypa/pip/issues/6440>`_)

19.1

=================

Features
--------

- Configuration files may now also be stored under ``sys.prefix`` (`5060 <https://github.com/pypa/pip/issues/5060>`_)
- Avoid creating an unnecessary local clone of a Bazaar branch when exporting. (`5443 <https://github.com/pypa/pip/issues/5443>`_)
- Include in pip's User-Agent string whether it looks like pip is running
under CI. (`5499 <https://github.com/pypa/pip/issues/5499>`_)
- A custom (JSON-encoded) string can now be added to pip's User-Agent
using the ``PIP_USER_AGENT_USER_DATA`` environment variable. (`5549 <https://github.com/pypa/pip/issues/5549>`_)
- For consistency, passing ``--no-cache-dir`` no longer affects whether wheels
will be built.  In this case, a temporary directory is used. (`5749 <https://github.com/pypa/pip/issues/5749>`_)
- Command arguments in ``subprocess`` log messages are now quoted using
``shlex.quote()``. (`6290 <https://github.com/pypa/pip/issues/6290>`_)
- Prefix warning and error messages in log output with `WARNING` and `ERROR`. (`6298 <https://github.com/pypa/pip/issues/6298>`_)
- Using ``--build-options`` in a PEP 517 build now fails with an error,
rather than silently ignoring the option. (`6305 <https://github.com/pypa/pip/issues/6305>`_)
- Error out with an informative message if one tries to install a
``pyproject.toml``-style (PEP 517) source tree using ``--editable`` mode. (`6314 <https://github.com/pypa/pip/issues/6314>`_)
- When downloading a package, the ETA and average speed now only update once per second for better legibility. (`6319 <https://github.com/pypa/pip/issues/6319>`_)

Bug Fixes
---------

- The stdout and stderr from VCS commands run by pip as subprocesses (e.g.
``git``, ``hg``, etc.) no longer pollute pip's stdout. (`1219 <https://github.com/pypa/pip/issues/1219>`_)
- Fix handling of requests exceptions when dependencies are debundled. (`4195 <https://github.com/pypa/pip/issues/4195>`_)
- Make pip's self version check avoid recommending upgrades to prereleases if the currently-installed version is stable. (`5175 <https://github.com/pypa/pip/issues/5175>`_)
- Fixed crash when installing a requirement from a URL that comes from a dependency without a URL. (`5889 <https://github.com/pypa/pip/issues/5889>`_)
- Improve handling of file URIs: correctly handle `file://localhost/...` and don't try to use UNC paths on Unix. (`5892 <https://github.com/pypa/pip/issues/5892>`_)
- Fix ``utils.encoding.auto_decode()`` ``LookupError`` with invalid encodings.
``utils.encoding.auto_decode()`` was broken when decoding Big Endian BOM
byte-strings on Little Endian or vice versa. (`6054 <https://github.com/pypa/pip/issues/6054>`_)
- Fix incorrect URL quoting of IPv6 addresses. (`6285 <https://github.com/pypa/pip/issues/6285>`_)
- Redact the password from the extra index URL when using ``pip -v``. (`6295 <https://github.com/pypa/pip/issues/6295>`_)
- The spinner no longer displays a completion message after subprocess calls
not needing a spinner. It also no longer incorrectly reports an error after
certain subprocess calls to Git that succeeded. (`6312 <https://github.com/pypa/pip/issues/6312>`_)
- Fix the handling of editable mode during installs when ``pyproject.toml`` is
present but PEP 517 doesn't require the source tree to be treated as
``pyproject.toml``-style. (`6370 <https://github.com/pypa/pip/issues/6370>`_)
- Fix ``NameError`` when handling an invalid requirement. (`6419 <https://github.com/pypa/pip/issues/6419>`_)

Vendored Libraries
------------------

- Updated certifi to 2019.3.9
- Updated distro to 1.4.0
- Update progress to 1.5
- Updated pyparsing to 2.4.0
- Updated pkg_resources to 41.0.1 (via setuptools)

Improved Documentation
----------------------

- Make dashes render correctly when displaying long options like
``--find-links`` in the text. (`6422 <https://github.com/pypa/pip/issues/6422>`_)

Links

• PyPI: https://pypi.org/project/pip
• Changelog: https://pyup.io/changelogs/pip/
• Homepage: https://pip.pypa.io/